The technique of rapidly scanning the magnetic field on the radio frequency to obtain NMR spectra has received further attention. The basic method consists of rapidly scanning a response, digitizing the analog data and storing the results in a Raytheon 704 computer. As long as the spin system can be considered as a linear and time-independent one, the response signals develop independently and without interference. The computer is then used to cross-correlate the response signals either with a suitable reference response or with an appropriate analytical function. The result is an undistorted spectrum with considerably improved sensitivity. The principal effort during this fiscal year has been to demonstrate the advantages of the method and also to determine its limitations. We have demonstrated the ease with which a portion of the spectrum of a protein in water can be scanned without recording the HDO or H2O peaks. This is a distinct advantage of the rapid scan method, since the pulse technique is severely limited due to the dynamic range problem. We have also developed a means using rapid scan to determine spin-lattice relaxation times. The approach, which is in some ways analogous to the saturation recovery method in pulse NMR is fairly general and good for both short and long times. Together with Professor Richard Ernst, I have investigated the effects of nonlinearity using rapid scan on coupled spin systems. We find both experimentally and theoretically that for certain scan rates there are phase and intensity anomalies which appear when large flip angles are used to drive the spin system into a nonlinear region.